(1) Field of the Invention
The present invention relates to a memory module indicator device.
(2) Description of the Prior Art
Conventionally, it has been a general practice to expand computer memory by connecting a standardized memory module to a general-purpose slot (socket) on a computer body. Available memory modules include, e.g., a 256-Mbyte DIMM (Dual Inline Memory Module) comprising eight 256-Mbit SDRAM (Synchronous Dynamic Random Access Memory) chips. Normally, the 256-Mbit SDRAM is provided with 13 address signal terminals A0 through A12 capable of connecting 13 row address signal lines and 10 column address signal lines. When the computer supplies address signals A0 through A12, data can be read and written to the corresponding addresses of all 256-Mbit areas in the entire SDRAM.
There is also known a memory card with access indicator as disclosed in JP-A No. 128511/1997. This memory card has an LED. When an R/W control signal becomes active, a timer starts to turn on the LED mounted on the memory card for 0.1 seconds. Here, the R/W control signal becomes active when data is read or written to the memory card. The LED lights independently of types of read and write operations.
Further, there is also known an IC card as disclosed in JP-A No. 266098/2001. This IC also has LEDs. As described in paragraph 0039 of JP-A No. 266098/2001, LEDs operate in response to an access request from a host apparatus. That is to say, a red LED and a green LED blink alternately each time operations to delete, write, read, or verify data are issued. Also on this IC card, the LEDs light independently of types of read and write operations.
On a conventional memory module, it has been difficult to know whether or not the mounted semiconductor memory operates.
The technologies disclosed in JP-A No. 128511/1997 and JP-A No. 266098/2001 indeed make it possible to notify whether or not a memory card or an IC card is accessed. However, the technologies are sometimes still inconvenient because they cannot indicate what type of access is occurring. Further, the LED indications are hard to understand and therefore not necessarily convenient, making it difficult to keep track of states of access to the semiconductor memory. In addition, it is not easy to confirm operations of the semiconductor memory built in a memory card or an IC card having no indicator element, sometimes causing inconvenience to users.